This invention relates to a method for cleaning and sanitizing a package containing an edible food product. The invention is particularly applicable to packaged food products distributed to hospital patients and later returned unopened to the hospital food preparation center.
More particularly, the invention is applicable to packaged food products, e.g. milk and fruit juices, that have previously been subjected to a heat shock treatment for prolonging and enhancing the shelf life of the product.
Milk and some juices are normally protected against spoilage by a pasteurization process. Typically, the pasteurization process involves heating the milk or other food to a temperature of about 175.degree. F. for a period of at least fifteen seconds. After the pasteurization process the pasteurized product must be kept in a refrigerated condition at a temperature not exceeding 45.degree.. If the pasteurized food item, e.g. milk, is left at room temperature for an extended period of time it will tend to spoil prematurely. Even when the pasteurized food product is kept in a refrigerated condition the shelf life is limited to a few days.
In an effort to extend the shelf life of milk, and other foods normally protected by the pasteurization process, a heat shock treatment has been devised. Such a process involves heating a raw milk product to a temperature of about 175.degree. F., and then exposing the milk product to an elevated temperature in the range of 285.degree. F. to 300.degree. F. for a period of about two to four seconds. The heat treated product is then cooled rapidly to room temperature, preferably in a time period not exceeding fifteen seconds.
The described heat shock treatment is often termed the UHT process. Milk, and other products subjected to the heat shock treatment, can be stored at room temperature for prolonged periods, e.g. longer than one month, without spoilage. The shelf life of the product is extended considerably while at the same time eliminating the need for refrigeration.
Prepackaged milk, protected by the UHT heat shock treatment, is often distributed to patients in hospitals as part of the daily meal. In some instances the patient leaves the milk package (carton) unopened. Hospital officials are reluctant to distribute the unopened milk packages to other patients, because of the risk that germs and contaminants may have been picked upon the outer surface of the package while the package was being handled by the initial patient.
Rather than risk the possibility that once-used (but unopened) milk cartons could become a mechanism for transferring germs and diseases from one patient to another patient, it has been the practice to destroy such unopened milk packages.
The present invention relates to a method for washing and sanitizing once-used (but unopened) packages containing milk or other edible product pre-treated with the UHT heat shock treatment. In the preferred practice of the invention, the unopened package is subjected to a three step process using the hospital's dish washing equipment, that includes washing the outer surface of the package with a detergent, rinsing the package outer surface with a solution containing a sanitizer (disinfectant), and drying the outer surface of the package. The sanitized package is then returned to the supply of packages being stored for distribution to hospital patients. New and once-used packages are co-mingled for distribution to hospital patients.
By using the method of the present invention it becomes possible to ensure that edible product in all of the packages is consumed, rather than being thrown away. The invention eliminates some wastage that would otherwise occur.
In order to enhance the effectiveness of the process for germ (contaminant) removal purposes, the washing and rinsing steps are preferably carried out at elevated temperatures in excess of 100.degree. F.
The washing and sanitizing actions can thus be accomplished relatively quickly, with relatively short time exposures to the elevated temperatures.
The general processes of washing, sanitizing and drying various items and materials have been previously known and practiced. U.S. Pat. No. 5,462,606, issued to John R. Burns on Oct. 31, 1995, for "Chemical Sanitizing of Foodware" discloses a dishwashing machine that includes mechanisms for washing and sanitizing dishes. U.S. Pat. No. 3,736,948, issued to Bert Crosswhite on Jun. 5, 1973, for "Washing and Sanitizing Apparatus for Carts such as Hospital Carts" shows and describes an apparatus for washing and sanitizing hospital carts. U.S. Pat. No. 4,702,777 issued to Henry Y. Kuhl on Oct. 27, 1987, for "Method and Apparatus for High Capacity Washing, Sanitizing and Drying of Stacks of Flats" illustrates an apparatus for washing, sanitizing and drying flat trays that are used to carry eggs.
The present invention applies the washing, sanitizing and drying operations to unopened packages containing edible products, e.g. milk, fruit juices, vitamins, etc. The invention is particularly directed to edible products that have been treated with the above-mentioned UHT heat shock process for enhancing the shelf life of the product. It is believed that the invention can be practiced in different environments, e.g. hospitals, prisons and restaurants.
Specific features of the invention will be apparent from the attached drawings and description of an illustrative apparatus that can be used to practice the invention. The invention relates to the method of treating the packaged food product, not the specific apparatus shown in the drawings.